That should get you started with a laterally moving object. Now what do you do if the object is coming at you??
Page 6
You still need to select some point of focus before you start. This would once again be an object in the foreground or the background itself.
Take my recent Jackass entry for instance. In this pic, the focus is on the shopping cart and the people. The blast cloud behind them is what I chose to set in motion.